Finding the Fourth Proportional to 1,978.13, 2,729.87 and 1,280.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.13 : 2,729.87 = 1,280.72 : x
2. Step 2: Convert to fraction form
   1,978.13/2,729.87 = 1,280.72/x
3. Step 3: Cross multiply
   1,978.13x = 2,729.87 × 1,280.72
4. Step 4: Simplify right side
   1,978.13x = 3,496,179.05
5. Step 5: Solve for x
   x = 3,496,179.05/1,978.13
6. Step 6: Final answer
   x = 1,767.42